Senstiehl



UNITED STATES PATENT OFFICE.

DANIEL AUGUSTE ROSENSTIEHL, OF PARIS, FRANCE.

PROCESS OF MAKING AZO COLORS.

SPECIFICATION forming part of Letters Patent No. 483,368, dated September 27, 1892.

Application filed March 2, 1892. Serial No. 23,508. (Specimens) Patented in PranceDecember 17, 1889, No. 202,675 in Germany December 20, 1889, No. 56,456, and in England April 15, 1890, No- 5,736.

T or whom it may concern.-

Be it known that I, DANIEL AUGUSTE Ro- SENSTIEHL, a resident of Paris, in the Republic of France, have invented a new and useful Improvement in the Manufacture of Azo Coloring-Matter, (for which I have obtained Letters Patent in France, No. 202,675, dated December 17, 1889; in England, No. 5,736, dated April 15, 1890, and in Germany, No.

I 56,4:56, dated December 20, 1889,) which improvement is fully set forth in the following specification.

The present invention relates to the production of azoic coloring-matters, derivatives I5 of the azoxyamines; and it consists in subjecting the product obtained by the union of nitramine with phenols and amines or their Az AzC I-I,

(3 H OH A20 C l-l AZ AZOH4 Two molecules of azo coloring-matter derived from the paranitraniline, less about three atoms of oxygen,

3511M a former patent, No. 380,927, granted April 10, 1888, to Poirrier and Rosenstiehl is described a process in which a nitramine is first transformed into an azoxyainine and then coupled with a phenol; but the process One molecule of azo coloring-matter derivation of azoxyaniline.

tire theoretical yield of para-azoxyaniline, products of a more advanced reduction are obtained at the same time, such as para-azoaniline,

Az G fL AzI-I Az C l-l Azl-l and the paraphenylene-diamine,

(3 H, (Ad-1 products of which the second at least constitutes a notable loss. On the other hand, by coupling at first the nitramine with sulphonapthol the result is a product soluble in Water, upon Which the reducing agents act uniformly, Thus the difficulties pointed out above are avoided, no insoluble matters have to be dealt with, the reaction does not go beyond the desired point, and the theoretical quantity of the desired coloring-matter is obtained.

Example I.Paranitraniline is diazotized in acid solution by known processes and is coupled with bisulpho-naphthol. The coloring-matter thus obtained, which dyes wool red in an acid bath, but not cotton, serves as the basisrin the process to bedescribed. Fifty-five kilos of this red coloring-matter are dissolved in two thousand seven hundred and fifty liters of water, rendered alkaline by means of seventy-six liters of caustic soda-lye at 40 Baum. The solution is heated to 80 centigrade, and there is poured into the same -under stirring a solution of 17.5 kilos of glucose in three hundred and fifty liters-of water. At the end of an hour the new coloring-matter is precipitated by common salt, which coloring-matter possesses the property of dyeing unmordanted cotton bluein an alkaline bath.

Example II.Nitro-orthotoluidine, fusible at 127 centigrade, is diazotized and coupled with alphasulpho-alphanaphthol, following for this preparation the general method well known to all chemists. 43.5 kilos of this red coloring-matter are dissolved in two thousand two hundred liters of water and forty liters of caustic-soda solution of 40 Baum. This solution is heated to boiling-point, and there are added fifteen kilos of arsenious acid, taking care to thoroughly'agitate the mass. At the end of one hour common salt is added, which precipitates the new coloring-matter in the form of a crystalline powder with green metallic luster. This matter dyes unmordanted cotton violet in an alkaline solution.

Example III.-Nitro-orthotoluidine, fusible at'107 centigrade, is diazotized and coup- Fortyled with alphasulpho-alphanaphthol.

five kilos of the red coloring-matter thus obtained are dissolved in two thousand two hun dred and fifty liters of water, to which are added fifty-six liters of caustic-soda lye at 40 Baum. After heating the solution to boiling-point there is introduced into it in small quantities ata time and under agitation 13.75 kilos of zinc powder of eighty per cent. of pure metal. At the end of an hour and a half the reaction is complete, and the new coloringmatter is precipitated by common salt. This coloring-matter dyes cotton red in an alkaline bat-h.

As reducing agents the above processes have been named zinc powder, glucose, and arsenious acid; but it is to be understood that other reducing agents may be employed, the essential featureof the invention consisting in taking the azo coloring-matter resulting from the coupling of a nitramine with a phenol, an amine, or their sulphonated carboxylated, or hydroxylated derivatives, and by a reduction in an alkaline medium transforming the same into coloring-matters derived from azoxyamines, which have the advantage over the first named that they dye vegetable fiber without mordanting.

Having now particularly described my said invention, what I claim, and desire to secure by Letters Patent, is

The process of producing coloring-matters, consisting in coupling a nitramine with a phenol, amine, or the specified derivative thereof and subjecting the product thus obtained to the action of a reducing agent in an alkaline medium, substantially as described.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

DANIEL AUG-USTE ROSENSTIEHL.

Witnesses:

J ULES ARMENGAUD, J eune, ROBT. M. HOOPER. 

